Understanding Thermoplastics

While you might be under the impression that plastic is just plastic, there are many different types of plastics created from many different types of polymers. Thermoplastic, for example, is a polymer that is easy to mold when it is heated to a specific temperature. This type of plastic is used for virtually all of the plastic packaging we see on store shelves, from the clamshells that hold strawberries to the blister packs that hold individual tablets of cold medicine to packages of batteries. But many more items are created using different thermoplastic polymers.

One polymer that is both strong and transparent is PMMA or Poly(methyl methacrylate). Of course, we all know this thermoplastic by brand names such as Lucite or perhaps Plexiglas. This type of thermoplastic is used to create many products, such as acrylic glassware or perhaps the huge glass enclosures at a zoo or aquarium. PMMA also is used to make the windows for airplanes and the exterior headlights and taillights of vehicles. Even doctors use PMMA to create dental fillings, dentures, bone cement and some types of hard contact lenses.

We’ve all heard of nylon, but you might not really think of it as a thermoplastic. The word nylon is actually the name for a category of synthetic polymers which first were produced in the 1930s. Today, nylon is one of the most frequently used polymers because it is resilient and durable. It also is very resistant to insects, mold and mildew. One of its first uses was to create durable parachutes during World War II when silk and hemp were in short supply. It is also used to make instrument strings, rope, tents and clothing. Of course, nylon is also used in the production of panty hose, which sometimes are simply called nylons.

Teflon is yet another type of thermoplastic and certainly one that is commonly known as the substance that keeps food from sticking to our cooking pots and pans. This synthetic polymer also goes by the scientific name of Polytetrafluroethylene or PTFE. Like nylon, this fluoropolymer was invented at DuPont albeit accidentally. Scientist Roy Plunkett discovered Teflon while trying to make a new type of refrigerant. This was in 1938, but it wasn’t actually used in cookware until the 1950s. It’s used for more than cooking; however, it also is used to make gears, bearings, fuel lines, computer mice and items made out of Gore-Tex.

When you think of PVC, you probably think about those white pipes, and it’s true that nearly half of the world’s pipes are made from this thermoplastic, Poly(vinyl chloride). Cheap to make and fairly durable, PVC is used in the production of hundreds of plastic items. In addition to pipes, consider the portion of the scientific name that also is quite familiar – vinyl. Many products are made from vinyl, specifically vinyl chloride or PVC. This includes everything from food storage containers to kiddie pools to stickers. PVC is water resistant and durable, so it is a handy material to you for vinyl house siding, mattress covers and shower curtains, as well.

In addition to the aforementioned thermoplastics, there are also polystyrene (PS), polyethylene (PE) and polypropylene (PP). Polystyrene is what is used to make Styrofoam for containers and packing materials. Polyethylene is used to make bottles and containers to hold different kinds of toxic chemicals as well as gasoline. So your gas “can” typically is made out of this plastic, as well as bottles that hold bleach, laundry detergent, drain cleaner and more. Finally, there is polypropylene, which is used to make heat-resistant plastic containers that can be placed both in the dishwasher as well as the microwave.

Lenna Stockwell loves writing about how stuff is made. For further information about thermoformed packaging or to know more about industrial thermoform, please check out the Indepak website today.